Anki Local HTTP Server Origin Validation Bypass

Publication date: 2026-07-07

Last updated on: 2026-07-07

Assigner: GitHub, Inc.

Description

Anki is a program for creating and reviewing flashcards. Prior to 25.09.3, Anki launches a local HTTP server to serve media files and web pages for parts of its interface, but requests from other origins were not sufficiently blocked. A malicious website could potentially trigger side-effecting requests to the local server, with severity varying by browser depending on Private Network Access protections. This issue is fixed in version 25.09.3.

CVSS Scores

EPSS Scores

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Meta Information

Published

2026-07-07

Last Modified

2026-07-07

Generated

2026-07-08

AI Q&A

2026-07-08

EPSS Evaluated

N/A

NVD

CVE-2026-59153

Affected Vendors & Products

Vendor	Product	Version / Range
anki	anki	25.09.3

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-346	The product does not properly verify that the source of data or communication is valid.

Attack-Flow Graph

Executive Summary

This vulnerability exists in Anki versions prior to 25.09.3, where the application launches a local HTTP server to serve media files and web pages for parts of its interface. However, requests from other origins were not sufficiently blocked, meaning a malicious website could potentially send requests to this local server. The severity of this issue varies depending on the browser's Private Network Access protections.

Impact Analysis

The vulnerability could allow a malicious website to trigger side-effecting requests to the local HTTP server that Anki runs. This could potentially lead to unintended actions or data exposure depending on the browser's security protections. The impact severity varies by browser, but it generally poses a risk of unauthorized interactions with the local server.

Mitigation Strategies

To mitigate this vulnerability, update Anki to version 25.09.3 or later, where the issue has been fixed.

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